Characterization of Pseudomonas aeruginosa affecting on somatic cell counts and antibiotics efficiency of bovine mastitis

Pseudomonas aeruginosa;bovine mastitis;type three secretion system (TTSS);biofilm;minimum biofilm eradication concentration (MBEC);636

수의과대학 수의학과 ;

University:서울대학교 대학원

关键词: Pseudomonas aeruginosa;    bovine mastitis;    type three secretion system (TTSS);    biofilm;    minimum biofilm eradication concentration (MBEC);    636;   

Others  :  http://s-space.snu.ac.kr/bitstream/10371/133690/1/000000008578.pdf

美国|英语

来源: Seoul National University Open Repository

【 摘 要 】

exoS, T, Y, and U. Among the TTSS-positive isolates, 69.4%, 8.3%, and 4.9% of isolates were invasive (exoU-/exoS+), cytotoxic (exoU+/exoS-), and cytotoxic/invasive type (exoU+/exoS+), respectively, based on the carried TTSS-related genes. Raw milk containing isolates possessed exoU showed higher SCCs than raw milk containing exoU-negative isolates. According to results of microtiter plate biofilm formation assay, most of isolates (97.5%) were biofilm producers. Majority of isolates showed gentamicin, amikacin, meropenem, and ciprofloxacin susceptibility at planktonic status. However, the susceptibility was decreased at biofilm status. Based on minimum biofilm eradication concentration (MBEC)/minimum inhibitory concentration (MIC) ratios, range of change in antibiotic susceptibility varied widely depending on the antibiotics (from ≥3.1-fold to ≥475.0-fold). These results indicate that the majority of P. aeruginosa isolates from mastitic raw milk in Korea had the genotype that may be related to SCCs increase. The efficiency of antibiotics therapy of bovine mastitis involving P. aeruginosa could be improved if MBEC as well as MIC test results would be considered.